Fluid flow mechanism



July 9, 1940. R. s. sMlTH FLUID FLOW MECHANISM Y 4 Sheets-Sheet l Original Filed Oct. 15, 19.34

July 9, 1940. R, 5 SMH-H 2,207,274

FLUID FLOW MECHANISM Original Filed 001'.. l5, 1934 4 Sheets-She-et 2 f Ilz venan Reuben fanleyjmii/z.

July 9, 1940. R, SMITH 2,207,274

FLUID FLow MECHANISM original Filed oct. 15; 1934 4 'sheets-sheer 5 July 9,1940- R. s. SMITH 2,207,274

FLUID FLOW MECHANISM Original Filed Oct. 15, 1934 4 Sheets-Sheet 4 In ven for Reuben ,fanlej ,S/dill.

llorzu/ Patented July 9, 1940 UNITED STATES FLUID FLOW MECHANISM Reuben Stanley Smith, Altadena, Calif., assignor to Smith Meter Company, a corporation of California.

Original application October 15, 1934, Serial No.

Divided and this application July 16,

1938, Serial No. 219,621

18 Claims.

This invention relates to fluid flow mechanisms adapted for use, for instance, as meters for measuring the volumetric ow of uids.

The instant application is a. division of my co- 5 pending application led October 15, 1934, Ser. No. 748,342 on Fluid iiow mechanism, which, in turn, is a continuation, in part, of my application filed May 29, 1933, Ser. No. 673,431 on Fluid flow mechanism.

In said copending application Ser. No. 748,342, certain broader claims are drawn to the vertical support of the rotor so it may be adjusted vertically with respect to the casing or the springsupport of the rotor so it is yieldably urged vertically upwardly with respect to the casing. The specific claims to these features in said copending application, are limited to structures wherein this relative movement of the rotor with respect to the casing is rendered possible by mounting the rotor shaft so it is vertically shiftable, the spring-support, where it is included as a feature, being applied between the casing and shaft.

As distinguished from these speciiic claims, the claims in the instant applic-ation, drawn to these features, are limited to structures wherein the relative vertical movement of the rotor with respect to the casing is rendered possible by mounting the rotor so it is vertically shiftable with respect to the shaft, the spring-support, where it is included as a feature, being applied between the rotor and shaft.

It is among the general objects of the invention to provide a fluid ow mechanism which shall operate with a minimum amount of friction and wear, an obvious advantage whether the device be used as a meter or motor. However, Without intending to limit my broader claims thereto, the invention is herein illustrated and described as a meter mechanism particularly well adapted for use in metering highly volatile fluids such as gasoline In this connection, it is my general objectto provide an extremely accurate metering mechanism,

The nature of the invention is such that further objects and features of novelty and advantage may be treated to better advantage as the detailed description progresses. Reference will be made to the accompanying drawings, in which:

Fig. 1 is a medial, vertical sectionl of a iiuid flow mechanism embodying my invention;

Fig. 2 is an enlarged fragmental section of the housing gasket shown in Fig. 1;

Fig. 3 is av section on line 3-3 of Fig. 1;

Fig. 4 shows the lower end of one of the rotor (Cl. 'I3-259) blades as viewed from beneath, at line 4-4 of Fig. 1;

Fig. 5 is a detached, ing base of Fig. 1;

Fig. 6 is an enlarged fragmentary section on line 6-6 of Fig. 1;

Fig. '7 is an enlarged fragmentary section on line l--l of Fig. 1;

Fig. 8 is an enlarged fragmentary section on line 8-8 of Fig. 1;

Fig. 9 is an enlarged fragmentary section on line 9 9 of Fig. 1;

Fig. 10 is a section on line I0-I0 of Fig. 3;

Fig. 11 is a section on line II--II of Fig. 3;

Fig. 12 is a fragmentary, bottom plan View of the roller support for the blade-unit of Fig. 1; and

Fig. 13 is a section on line I3-I3 of Fig. 12.

The meter housing or casing is generally indicated at II) and includes an annular body member or barrel I I and end plates or closures I2 and I3. Since, for reasons to be made apparent, it is desirable that the meter be positioned with its rotor axis extending vertically, I will individually term plate I2 a cap or cover member and plate I3 a base member. However, this terminology is not to be considered as limitative on the invention except as to such claims as specifically call for these particularities. It is further to be noted that where, in my claims, I refer to certain relationships between the rotor and parts integral with the casing, that reference is to be construed as including situations where the parts may be separate from but associated with the casing, unless it is otherwise indicated in particular claims.

Barrel II is flanged at I4 and plates I2, I3 are anged at I5 to take bolts IG whereby the casing parts are held in assembly.

As will appear, it is important that the opposed faces I8 and I9 of plates I2 and I3, respectively, be maintained accurately in predetermined spaced relation, and, of course, the joint between the barrel and end plates must be duid-tight. Accordingly, iianges I5 are brought tightly down on anges I4 to set faces I8 and I9 with the predetermined spacing, while gaskets Il, interposed between flanges I4 and I5 are of such thickness that they may be compressed suiciently to allow this contact and yet insure a huid-tight joint. Gasket I1 is fitted in the groove 4 sunk in the inner face of ange I5 (Fig. 2) the t being such that the gasket will come off with the cover when the latter is removed. Clearance grooves 5 and 6 are cut in the opposed face of flange I4, groove top plan view of the hous- 6 extending to the inner peripheral face of annulus Il, though the corner is preferably chamfered as at 1, while groove 5 extendsrradially beyond each side of annular shoulder 6 defining the outer extent of groove 4. Any excess packing in groove 4 will be taken in clearance grooves E and 6 when the housing parts are initially assembled, assuring that the outer extent of the flanges may come into metal-to-metal contact and thus definitely space faces i8 and i9, Likewise, these grooves are adapted to receive the mutilated or mashed edges of the packing which may result from removal of the cover, though the chamfer 1 and grooves 5, 6 together with the recessing of the gasket into the underface of flange i6 practically eliminates the danger of damage to the gasket during cover removal.

Face i8 is annular, as viewed in plan, (Fig. 5) the base within that annulus being depressed to form a settling chamber 2! defined by substantially vertical wall 22 and conical wall 23.

Extending upwardly from base I8 into settling chamber 2l are spaced bosses 24, 26 and 28 (Figs. 1 and 5). Vertical rib 21 connects bosses 24 and 25, while rib 21' connectsv bosses 26 and 26. A short radial rib 21" extends from hub 34 to wall 22, a rib 28 connecting this cross-partition with boss 24. Extending from boss 26 toward but stopping short of cross rib 21", is a rib 29, a drain port 28a closed by plug 28h being disposed between the end of rib 29 and rib 21".

An annular baiile plate or settling-chamber cover 30 is disposed on top the bosses and partition T formed by the several ribs which extend substantially centrally through the annular settling chamber, it being noted by reference to Fig. 1 that cross rib 21" is a little lower than the other ribs to provide clearance space 3| beneath the cover 30. Cover 30 is held in positionby flush-head screws 32, the positioning being such that there are provided slight annular clearances 33 and 33 between the cover and settling-chamber walls 23 and 22, respectively.

Extraneous matter in the iiuid within the rotor (to be described) nds its way into the settling chamber through clearances 33 and 33', falling to the bottom of that chamber. Thereafter the fluid swirling beneath the rotor is prevented from picking up this matter and returning it to the rotor assembly. Any tendency of the swirling fluid to set up cross currents in the settling chamber, and thus carry out the' debris, is checked by partition T, while partition 21" checks the tendency of the uid to swirl circumferentially of hub 34 beneath the settling chamber cover 38.

Base wall 23 deiines a central hub 34 having a bore 35 and a conical counter-bore 36, keyway 31 being sunk in the wall of bore 35. Bore 35 is adapted to take the lower end of the cam shaft 40 in a manner later to be described, upon which shaft the rotor assembly or impeller mechanism, generally indicated at R, Yis mounted.

As will\appear, the rotor, cam shaft, rotor blades, operating cam, etc., may be assembled to form a rotor unit which is capable of bodily insertion in or removed from housing Ill when cover i2 is detached. Accordingly, I will first Set forth the make-up of that unit.

Referring to Figs. 1, 3 and 10 it will be seen that the rotor includes an annular body member or carrier 4l (preferably, though not necessarily, of cast aluminum) having a downwardly and outwardly inclining web 42 extending across the bore 43 thereofl at a point spaced downwardly from its upper end, the web being ribbed at 44 and supporting a hub 45 which has a bore 4B and a. counterbore 41. The described location of the web provides, in effect, a recess at the upper end of the body to allow the interposition of a gear (later to be identified) between the rotor and cover l2. The conical characteristics of web i2 contribute to its efficiency in stifl'ening the body member and resisting the tendency of its split side-walls to be relatively displaced in a vertical direction.

An irl-turned flange 48 is provided at the lower end of the body member. The annular wall 66 o! annulus or body member 4I has four radial slots 5i, equally spaced apart and extending from top to bottom, flange 48 and web 42 having slots 52 (Fig. 12) and 53 (Fig. 1) respectively, which register with opposite ends of slots El. However, slots 52, 53 may be somewhat wider than slots 5l to provide for greater blade-clearance. Internal ribs 56 extend vertically along wall 50 adjacent the slots, serving not only to strengthen the structure at these points but also to increase the extent of surface presented to the side faces of the blades which play through these slots, as will be described. Horizontally extending, annular ribs 65 further strengthen the structure.

Midway between each pair of slots 52, flange 48 has a raised boss 58 which is drilled to receive a removable hinge-pin 59 (Figs. 10 and 11) adapted to project into the alined bore of boss 60 which extends downwardly from web 42.

There are provided two blade units generally designated at 6l and 61a, (Figs. 1 and 3), each unit embodying a pair of blades 62 connected by yoke 63, the lower ends of the blades being extended inwardly or towards each other as at 64. The two blade units are individually fashioned so that the yokes thereof will be spaced apart vertically and lie at opposite sides of section line 3 3 of Fig. 1 when, with their extended ends 64 facing downwardly in both cases, they are assembled in the rotor body. Otherwise, they are substantially alike.

Each blade unit has a pair of opposed shoulders 65 adjacent the inner edges of the blades and extending vertically from yoke 63. Said shoulders preferably are arcuate, as viewed in plan, being struck about the yoke axis as a center. Preferably, though not necessarily, the units are of cast aluminum, giving them requisite strength with desirable lightness.

Mounted for pivotal movement on spindles 58. are two rock arms 69 and two rock arms 68a, the diametrically opposite arms 69 being adapted to coact with blade unit 61a and diametrically opposite arms 69a being adapted to coact with blade unit 6l. 'Ihe vertically spaced and drilled lugs 10 of the rock arms are fitted between bosses 56 and 60, through which lugs and bosses the spindles 59 are thrust. The knurled ends 1| on spindles 59 frictionally grip the walls of the recesses lla in which `they seat, in order to prevent the spindles from vertical dislodgement, though the spindles may be wilfully dislodged for purposes of armi-disassembly, by tapping their' upper ends where they extend above web 42. The application of a removable cap (to be described) to the lower end of the rotor, also serves to prevent the spindles from accidentally dropping out of place.

Cast into the free ends of each rock arm is a stub shaft or spindle 12 upon which an antifriction ,roller assembly 13 is mounted, this assembly consisting of bushing 14 surrounded by or followers and roller assemblies 11 will be races and balls 16. Engaging the inner race is a spacing bearing washer 16' (Figs. l0 and 11) which, in turn, opposes an anti-friction roller assembly 11 similar' to assembly 13 but capable of rotation independently thereof. The two rollers on a given spindle are retained against dislodgement therefrom by wire-and-ring retainer 18, For purposes of later distinction, roller assemblies 13 will be termed cam rollers termed shuttle rollers.

It will be noted that While the spindles 12 of arms 69 extend upwardly therefrom and the spindles of arms 69a extend downwardly there- 16 from, the several arms are so fashioned that the cam rollers 13 of all arms lie in the same horizontal plane, which plane is substantially midway between the top and bottom of body member 50.

A uniformly accelerated motion cam 80 is keyed to shaft 40 at 8|, the shaft extending upwardly between the arms of yokes 63, and the cam being positioned in horizontal alinement with the cam rollers 13 of all the rock arms, which positioning holds the rock arms so their shuttle l5 rollers 11 are held in engagement with shoulders 65 of the blade-units.

It will be seen that shaft is stationarily centered in the housing by bore 35, key 83 in way 31 establishing the position, as viewed in plan,

80 of the shaft and hence of cam 80 with relation to the casing walls which define certain flow passages to be described. Inner race 85 of radial bearing 86 lies between the top of hub 34 (Fig. 1) and annular shoulder 81 on shaft 40. A longi- 38 tudinally-split wedge cone 88 is entered in counterbore 36 about the shaft, the cone having a keyway 89 to accommodate key 83, and nut 90 is threaded on the end of the cam shaft and turned up against wedge cone 88, forcing it 40 tightly into counterbore 36 and bringing shoulder 81 tightly against race 85, thus tying the cam shaft rigidly in centered position with respect to base I3 and barrel Il.

A lock washer 9| may be interposed between the cone and nut, with onelocking lug 92 turned into keyway 89 and another locking lug 93 turned against a side face of the nut. Suitable clearances 94 and 95 are provided to prevent premature shouldering of the shaft-holding assembly, and to permit subsequent take-up of that assembly should occasion therefor subsequently arise. A protective cap 96 is bolted to the underside of the base to protect nut 90 and the end of the cam shaft, and also to seal off fluid which (i5-may leak through the cone-splits.

Cam 80 is held in engagement with an integral, upwardly facing shoulder 91 provided on cam shaft 40.

When cover l2 is placed in position, its under- 00 face |8 engages annular shoulder 98 of the cam shaft, and a nut 99 is threaded on the end of that shaft (which projects through and to a point above cove I2) to take the cover tightly down onto shoul er 98. Thus, the cam shaft with its nuts .and shoulders, serves as a tie from cover to base at the center of the meter, giving obvious structural advantage, particularly where relatively high internal fluid pressures may develop.

The outer race of radial bearing 86 has sliding fit within bore H3 provided in hub ||4 of deand to maintain bearing 86 always in a condition to prevent radial displacement of the lower end of the rotor and thereby preserves predetermined radial clearance between the rotor elements and opposed walls of the casing. Spring ||2 also permits limited vertical movement oi cap ||5 along shaft 40 when the rotor, proper, ls moved along that'shaft either by adjustment or vertical jar, as will be described.

Rotor cap I I5 is preferably conical, sloping outwardly and downwardly from hub ||4, and is provided near its outer edge with drainage ports I6 whereby foreign matter'from within the rotor may drop into settling chamber 2|. The cap has an annular flange ||1 provided with four radially extending slots ||8 (Figs. 12 and 13) which are adapted to register with slots 52 in flange 48 of member 4I. The conical nature of the cap and the downwardly extending annular'flange ||5a thereon (Fig. 1) serve, when the cap is applied to the rotor, to stiifen the rotor structure in a manner effectively to resist relative displacement -of the sections of the split rotor body.

On opposite sides of slots ||8, are arranged press-fitted pins |20 (Figs. 12 and 13) these pins extending through flange ||1 and its annular groove |2| into registering holes in flange 48. Flange ||1 also has a counter-groove |2|a concentric with groove |2|.

Hardened rollers |22 (Figs. 1, 12 and 13) having rotational bearing on shafts |23, preferably by way of roller bearings |22a, are positioned in slots ||8, shafts |23 lying within groove |2| and being held against longitudinal displacement by pins |20, as clearly shown in Fig. 13. Spring clips or retainers |24 are applied to the underside of cover ||5 by screws |25 which extend into threaded engagement with flange 48, thus serving not only to hold the clips upwardly inposition but alsotohold the cover tightly in assembly with rotor body 4|. The clips lie within and approximately fit counter-groove |2|a, thus being prevented from accidentally rotating from beneath shafts |23. The clips are adapted to hold the shafts in such positions that they support the rollers in a position to be engaged by the lower edges of blades 62, the blades thus being anti-frictionally supported from beneath to contribute to their ease of shuttling movement, as will be described. It will be seen that the inward extensions 64 of the blades assure the roller-support of said blades even when they are in their positions of greatest projection, as at the left of Fig. 1. The rollers are preferably of such diameter that the lower edges of the blades are flush with the bottom face of ange 48 and hence with the lower end of the rotor body.

Pins |20 form a tie between cap ||5 and annulus 4| at opposite sides of slots 5I, serving to hold the slotted end of the annulus from spreading and thus definitely and permanently establishing the widths of said slots so that predetermined clearances between the slot walls and blades 62 are exactly maintained.

A radial and thrust bearing unit, generallyv manner to preserve predetermined radial spacing between them and the meter casing,

Plate I3`I carries an integral, annular pinion |36 on its upper side, while thrust bearing |34 is interposed between its lower face and radial bearing |33. Shaft 60 extends with annular clearance through the upper race of bearing |95 and the bore of pinion |30, the lower race oi bearing i3d resting on top the inner race ci' bearing The inner race of bearing i533 rests on a col lar |39 which is vertically slidable on shaft dil, the collar, in turn, being resiliently supported by compression spring 30 surrounding the shaft. The lower end of spring 38 seats on cam 90, which cam, from this aspect, represents an upwardly facing shoulder on the shaft. With the above cooperation existing between the several bearing and rotor elements, it will be seen that the entire rotor is vertically and resiliently supported by spring 39, and thus resiliently supported and capable of relative vertical movement with respect to casing i0.

The opposite ends of blades 02 and of rotor annulus il are accurately machined to allow for slight clearance, indicated at K, between those ends and opposed housing faces i8 and i9. In the drawings the clearances are exaggerated, as is true of all other clearances indicated, in order that they may show up in the relatively smallscale drawings.

The mechanism to be described is provided for the accurate vertical adjustment of the rotor annulus and its blades to locate them properly with respect to faces I8 and I9 and to preserve that relationship in spite of the constant tendency of spring 38 to urge the rotor assembly upwardly. For instance, in giving this description it will be assumed that the rotor and the blades are. .010" shorter than the distance between faces I8 and I9 and that it is desired that the rotor finally be positioned so there is .005" between each of its ends and the respective opposing faces I8 and I0. it being understood that this particular dimensioning, while giving satisfactory results, is not to be considered as in any way limitative on the invention but is given merely for the purposes of illustration.

Sliding collar |38 carries a cross-head I 39 which is in the form of a cylindrical pin extending through a vertically elongated cross-slot |40 in cam-shaft 40 (Figs. 1 and 9). Intersecting slot |40 and extending therefrom axially of the shaft to the upper end thereof, is bore |4|, the upper end of this bore being internally threaded at |42. A depressing plunger or actuator |43 extends through the smooth portion of the bore and projects lnto slot |40, where it bears at its lower end against pin or cross-head |39, the latter preferably being milled at at |44 to receivethe end of the plunger, the milling forming, in effect, a cross-head socket, and the seating of the plunger in this socket limiting longitudinal movement of the cross-head to prevent; its horizontal displacement.

In order to hold cross-head |39 against rotation, which might otherwise carry fiat |44 out of proper alinement with plunger |43, I provide said cross-head with a pin or key |45 (Fig. 9) which fits within the keyway r slot |46 of collar |38. Collar |38 and cross-head |39 may be considered as together making up a member slidable longitudinally of the shaft.

Threaded in bor'e |4I at |42, is an adjusting or control plug |41 having a head |40 (Figs. 1

and 8) provided with spanner-wrench sockets |40 and a serrated or notched edge |00. A lock or jamb nut IBI is threaded on the plug against the end 'of the cam shaft. Nut IBI is adapted to coact with the top of the shaft to take up any thread-looseness between the adjustment plug and the shaft and thus minimize leakage through the thread-joint.

it will be seen that 'spring 00 exerts a com stent tendency to move collar i230 and hence (through the inner race oi bearing its and through thrust bearing i3d) to move the rotor with all its contained parts upwardly toward cover I2. The upward extent of this movement is limited by plunger |43 and adjustment plug |41, it being obvious that by unscrewing that plug, the spring is allowed to raise collar |38 and hence rotor R upwardly a corresponding distance, and that opposite movement of the plug depresses the sliding collar against the tension of spring 0B to allow the rotor and its parts to descend by gravity a corresponding distance. Thus, ny proper manipulation of plug |41 it will be sels the rotor may be adjusted vertically within the housing (rollers 13 merely sliding vertically over the face of cam during this adjustment) in order to give the desired clearances between housing faces I8, I0 and the opposite ends of the rotor and blades.

The extent of possible vertical movement of .the rotor along the shaft is limited, prior to the inserting of the assembled rotor and shaft in the housing, by the vertical extent of slot |40, though it will be understood that when the rotor is assembled with the housing, cross-head |39 never reaches either end of the slot. When so assembled, the lower end of plunger |43 may be considered an adjustable stop for the cross-head and collar;

Bolted to cover I2 at I50a. and overlying the upper end of shaft 40 with its nuts 00, ISI and plug |41, is a cap IBI'. (Figs. l, 6, '7 and 8) having internal lugs |5|a (Fig. 6) and teeth |52 (Fig. 8) serving, respectively. t0 engage the corners of nut 99 and the notches |50 of head |49v to hold said nut and the adjustment plug in adjusted positions. The cap also serves as a protector for the elements housed therein, and preferably a gasket |54 (Fig. l) is interposed between cover I2 and cap IBI to prevent leakage of fluid which may ilnd its way into the cap-interior around the shaft or through its terminal bore.

Vertical adjustment of the rotor may be accomplished as follows. With cap IBI removed and nut |5I loosened, plug |41 may be backed out to an extent that will allow spring 33 to lift the 4rotor to a position Where the upper end of the rotor-annulus 4| engages the under face I3 of cover I2. Plug |41 is then screwed down, in a manner to compress spring 38 sufficiently to allow the rotor to drop until its lower edge engages base-face I9, which condition may be determined by reaching through side openings |00 and ISI (Fig. 3) in body member il (the position of which openings will be later set forth) and noting the resistance set up when the rotor is thus turned by hand.

Threads |42 and notches |50 in head |43 are so related that the assembler can thereafter accurately set the rotor with predetermined clearances between it and the end plates of the housing. This is done by unscrewing plug |41 a predetermined amount. For instance, threads |42 may be twenty to the inch and there may be fifty notches in head |40, this example being given merely by way of illustration. Hence an angular movement of the plug equal to the extent of one fange-notch will move the plug longitudinally .001". Thus, the assembler may rotate plug |41 left-handedly (assuming threads |42 are righthand) through the angle represented by ve notches, allowing spring 38 to raise the rotor .005", thus creating a clearance of like distance between face i9 and the bottom of the rotor and lower edges of Iblades 82, still leaving a like clearance between face |8 and the top o! the rotor and the upper edges of the blades, it being remembered that in the example given, a total clearance of .010" was assumed.

Nut |5| is then tightened and cap |5I is applied, with its teeth |52 engaged in notches |50 to hold the plug in adjusted position, it being noted in this connection that cap lugs |5|a are suiliciently coarse to insure that their effective cooperation with nut 99 does not interfere with the proper engagement of teeth |52 with notches |50, irrespective of which individual teeth engage which individual notches.l

It will thus be seen that the down-bearing load of blades 62 is imposed entirely on rotor body 4| and the down-bearing load of the rotor is taken ona thrust-bearing which is spring-supported from the stationary shaft and hence from the casing, all in a manner to maintain the blades and rotor body in predetermined, vertically spaced relation with the underlying wall I9 of the casing.

'I'he arrangement just described is, of course, operative to eiect re-adjustment of the rotor uriit should need for same arise during subsequent operation.

With shaft 40 and its cam 80 centered in housing I0, with thrust bearing |34 taking the downbearing load of the entire rotor and blade unit, and with radial bearings 86 and |33 interposed between the shaft and rotor, it will be seen that the rotor and its parts are mounted for exceedingly free rotation, though accurately held in proper allnement and spacing both vertically and radially with respect to all associated housing parts.

Cam is, of course, held by shaft 40 stationary with respect to housing I0, and, since the opposed rollers 13 of each blade unit engage the cam at diametrically opposite sides, rotation of rotor body 4| causes shuttling of the blades, as will be described in detail later. However, due tol the interposition of shuttle rollers 11 and blade supporting rollers |22, the resistance offered to this shuttling movement and hence tol bodily rotation -of the rotor is reduced to a minimum.

'I'he mounting of rollers 13 and 11 on rock arms 69 and 69a contributes greatly to the smoothness and ease of rotor rotation and eliminates much wear and undesirable side pressure that would otherwise occur between the blades and the walls of the slots through which they reciprocate. The cam rollers 13 take the thrust of the cam, which thrust is transmitted through the rock arms and shuttle rollers 11 to the blade unit, but, as applied to a given blade unit, the thrust is only in the direction of its shuttling movement, that is, radially with respect to the rotor and hence with no side-thrust component.

It will be noted that rollers 11, through which the shuttling thrust is transmitted to the blades, are, on one pair of arms 69a, above the plane of cam 80 and, on the other pair of arms 69, are below that plane, in each case the rollers being located approximately in the horizontal plane in which lies the center of mass of the associated blade unit, it being noted that the yokes of the two units lie at opposite sides of cam 80. With -this relationship existing there is eliminated any tendency for the blade units to tilt under thrustload and cause contact and consequent wear between the blades and surfaces adjacent thereto.

Not only is this elimination important from the standpoint oi' lengthening the actual life of the meter, but it is also important as a factorin preserving meter accuracy, for not only would this wear bring about an undesirable increase in certain relatively critical clearances, but also, during the period of contact causing that wear, a considerable and undesirable frictional hold-back on the rotor would result.

Since shoulders 65 are located immediately adjacent the yokes 53 which connect the blades of a given blade-unit, the tendency of rollers 11 to spring the blades apart is minimized, to obvious advantage. Preferably, the yoke arms are connected by cross ribs |56 (Fig. 9) to stiften the yoke structure and give the blade-unit-casting greater torsional resistance.

The wide spread of the rock arm lugs 10 (Figs. l0 and 11) withvrollers 13 in planes substantially midway between those lugs, eliminates any undesirable deilection which might otherwise arise from the fact that the thrust load is transmitted from the rollers 13 in one plane and to rollers 11 in another plane.

It has been noted that rotor R. is resiliently supported by spring 38 in predetermined, vertically spaced relation with respect to face i9. Consequently, ii the rotor be exposed to a downward jar as may often be the case, particularly where it is mounted on a tank car or delivery truck, this jar as imposed on the rotor 'is absorbed by spring 38, the latter yielding to allow the rotor to descend through the slight clearance vspace between face I9 and the bottom of the rotor, thus relieving thrust bearing |34 from the solid shock to which it would otherwise be exposed.

If the shock be severe, the rotor may momentarily contact face I9, but even if this happens the shock is taken evenly over the entire under face of the rotor, the possible load transmitted to the ball thrust bearing being at all times' limited to the spring pressure which is Well within its capacity to withstand.

Preferably, though not necessarily, hard-metal inserts |51 (Figs. l and 4) are cast into the lower, inwardly extending edges 64 of blades 62, providing wear shoes for engagement with ball-bearing rollers |22. The inserts have upwardly extending and spaced lugs |58 which are pierced as at |59 so, in casting the blades, the metal will run into the piercings and between the lugs to key the shoes solidly to the blades.

Now referring to Fig. v3, it will be noted that an annular ow channel, generally indicated at C, is dened by the inner wall of casing I0 and the periphery of rotor annulus 50. Opening to this channel are housing ports |60 and IBI, these ports extending through bosses |62 adapted to take attachment ttings (not shown) whereby flow pipes may be applied to the meter. The meter is symmetrical and functions properly irrespective of the direction of uid ow therethrough. Consequently either port may be utilized as inlet or outlet, but, for purposes of description, it will be assumed that the rotor is to rotate in a clockwise direction, and accordingly port |60 will be considered as the inlet and port |`4| as the outlet. 'I'he size and shape of the ports may vary within wide limits, as long as certain fundamental relationships are preserved, as

'will be set forth later, and therefore the following description is not to be considered as in any way limitative on the invention except insofar as the claims may import. M

Ports |60 and |'6I are spaced apart approximately and are elongated vertically so they are substantially of the same vertical extent as flow channel C. The ports are substantially arcuate as viewed in plan and their dimensions are such that, throughout their lengths, their cross-sectional areas are substantially equal to the cross-sectional area of the flow channel C, which latter is substantially of uniform crosssectional area throughout. The significance of this relationship will be pointed out later.

Interposed in flow channel C at a p oint between ports |60 and |6| is a barrier block |66 (Figs. 1 and' 3) consisting of an arcuate plate portion |64 held in annularly spaced relation with the housing by marginal flanges, the horizontal fianges being indicated at |65 and the vertical flanges being indicated at |66. 'I'he block is detachably held in position by screws |61 extending through barrel though it will be understood the block may be considered as a part of the casing. The outer faces |66 of vertical flanges |66 are arcuate as viewed in plan-sectiomand fit along the edges |69 of the associated housing ports Where they open to the housing bore. Flange faces |68 thus form smooth continuations of the adjacent wall faces |10 of the associated inlet walls, said faces and walls curving inwardly and face |68 being in a position to deliver uld. at the inlet port, in such a direction that it more or less directly impinges against the rotor at I, where, due to the described curvature of the inlet faces (of which |68 may be considered a part) the pressure of the fluid is increased at this area of impingement, while, at the outlet side, the pressure adjacent the rotor is relatively reduced, resulting in a pressure-clierential that tends to increase slippage across the ends of the rotor from inlet to outlet.

Now it will be seen that uid slippage from inlet to outlet is not only proportional to the pressure differential between ports but is also proportional to the time element. For instance, in passing gals. if the now rate be 50 gals. per minute, there are two minutes during which slip may occur. If the flow rate be 100 gals. per minute, the time for slippage is reduced to one minute. It is therefore desirable to increase the slippage at high flow speeds, for the naturally greater pressure differentials which then exist are not sufficient to produce the necessary amount of increased slippage. The provision set forth above for increasing the slippage by virtue of the curved inlet and outlet walls and the more or less direct impingement of the fluid on the rotor, accomplishes the desired end.

The face of block |63 is recessed from top to bottom to provide a clearance passageway |1| between the rotor and the block. This recession leaves vertically extending lugs |12 and |13 at .the end of the block, which lugs are spaced apart slightly less than-90 and establish diminished clearance passageways |14. Taken together, passageways |1| and |14 will be considered a return or corrective passageway P, the significance of which will be pointed out later.

Block |63 has a pair of horizontal ribs |63 between flanges |65 and has a pair of ports |1,|'

and |12 extending through portion |54, both these ports opening to space |12' between the plate portion |64 and housing annulus port l 1|' being immediately below upper flange |65 and port |12' being approximately midway between the lower rib |63' and the bottom flange |65. These ports prevent the trapping of air in passageway P, and solid foreign matter, which may nd its way into that passageway along with the fluid, is free to pass through the ports into space |13' where it settles out, the space thus serving as an auxiliary settling chamber.

Diametrically opposite block |53, the inside of the housing wall is accurately machined at |15 (Fig. 3) throughout an angular extent of a little more than 90, this portion of the wall and the opposite wall of the rotor annulus defining the sides of measuring chamber M which is. of course. a part of fiow channel C. 'I'he measuring chamber is defined at top and bottom by faces I6 and 9, and at its ends by any two adjacent rotor blades when they are both within the limits of face |15. The dimensions of the measuring chamber are such that its volumetric capacity will have a known value to which a meter counter or register may be accommodated by operation, for instance, through a properly calculated gear train to register in any chosen unit of measure. e

Cam 60 is so located that, upon rotation of the rotor, a given blade is projected to its furthest extent a few degrees before it reaches the measuring chamber, the opposite blade of that unit simultaneously reaching its position of full retraction (preferably a little below the peripheral face of the rotor to insure ample clearance with respect to the block-lugs |12, |13) just prior to reaching lug |12. The cam rollers 13 of that unit then ride over cam dwells |16 and |11 which maintain the blades in their respective positions of full projection and retraction until `iust after they leave the measuring chamber and lug |13, respectively. The path of a given blade during one revolution of the rotor is indicated in dotted lines 'G in Fig. 3.

With the described relationship of wall |15, abutment wall |64 and ports |60 and |6|, it will be seen that casing I0 may be considered as having oppositely disposed segmental cylindrical walls of different radii with inlet and outlet ports intermediate the ends of said wall.

The rotor blades during their passage through measuring chamber M, preferably slightly clear the defining walls of that chamber, the rotor clears lugs |12, |13, and the side walls of the housing are cut back between the measuring chamber and ports |60, |6| as at |18, there consequently being no metal-to-metal contact to cause a frictional drag on the rotor. It has been Apreviously made apparent that due to the cam rollers, shuttle rollers and blade-supporting rollers, together with their particular dispositions, there is little resistance offered to rotor movement by the internal mechanism thereof. It follows that the rotor is capable of smooth and easy rotation under the slightest of impulses, a factor of great importance, as will be realized.

Before proceeding to a brief description of the register drive, I will discuss the functioning of the assembly so far set forth, for it will be realized that this does not depend upon particularities of that drive. However, for purposes of immediate reference, a registering mechanism will be designated generally at S (Fig. l) it being understood preliminarily that register S is operated by virtue of rotor movement.

When the meter is initially connected with a source of -uid under pressure, plug |80 in cap |2 (Fig. l) is temporarily removed to permit the escape of air which may be trapped in the upper part of the housing.

As the fluid flows through inlet |60, it is guided by the smoothly curving walls of the inlet passageway and wall |68 into flow channel C. In its passage, the fluid acts against such rotor blades as are in its path in a manner to cause rotor rotation which, in turn, shuttles the blades in the manner previously described.

The feature of maintaining the inlet and outlet and the flow passage C of substantially uniform cross-sectional area throughout (though they may vary inshape at different points in their extents) allows the maintenance of a substantially constant flow-velocity through theA meter, the measuring of the uid being accomplished without stopping or retarding the flow and therefore without wasting head energy.

With it resulting that there is no substantial differential ln pressure from inlet to outlet, the tendency toward variational fluid-slippage is reduced to a minimum, and consequently the rotor movement may correspond very nearly exactly to the fluid flow, and the rotor is capable of operating under extremely low pressures.

Due to the mounting and association of the various moving parts, as explained above, but little resistance is offered to rotation of the rotor and therefore but little resistance is offered to flow of fluid through the meter. In this connection it is to be noted that, since the blades are being bodily carried in the direction of fluid flow and at practically the same velocity thereas, said blades do not, by virtue of radial movement through the fluid stream to their projected positions, appreciably retard the passage of the fiuid from the inlet to the measuring chamber.

Cam 80 being of the uniformly accelerated motion type, accomplishes the shuttling movement of the blades in the manner best adapted for smooth, even, shockless operation.

Centrifugal force tends to hold each blade successively outward as it is extended beyond its central position, thus holding the associated cam roller rmly in contact with the small-radius dwell |11 during movement of the given blade through the measuring chamber. This insures that the blade will clear measuring-chamber wall |15 by a predetermined extent as at L (Figs. 1 and 3) in spite of lost-motion or play in the mechanism, thus insuring predetermined slippage through the slippage clearances or channels and consequent accurate metering results.

The described nature of the cam and blade units, the free shuttling movement of the blades and the means for transmitting thrust from the cam to the blade unit, all contribute to the end that the energy transmitted to the blades from the rotor during their radial acceleration period f is returned to the rotor during their radial -deceleration period.

The face I9 of base I3 is recessed at |8I, the recesses starting at points opposite the inlet and outlet ports and terminating in substantially square-cut, vertical shoulders |82 adjacent the ends of measuring chamber M. Sand or other shoulder |82 and drop into the recess, thus preventing scoring of the fioorof the measuring chamber or damage to the ends of the blades, and eliminating frictionaldrag or jamming which might otherwise occur.

There will be some slippage of the fluid through channels defined by internal housing faces and the opposed faces of the rotor and blades, and consequent leakage into the interior of the rotor, though, during operation of the meter, slippage through lslots 5| into the rotor is reduced to a minimum since the blades, as they enter the fluid body, are being projected in a'direction tending to counteract such slippage ow. Openings 53 and 6 in web 42 and cap ||5, respectively, put the space above the rotor web and the interior of the rotor into communication with the settling chamber 2|, and, assuming gasoline is the fluid being metered, water present in the fluid may be occasionally drained by removing plug 28h (Fig. 1).

Such fluid as slips past the blade or across the ends of the rotor (and which may be considered as passing from inlet to outlet through slippage channels K and L dened by the opposed and spaced walls of the casing and rotor elements) is, of course, unmeasured since it is not represented by an effective impulse on the rotor blades, and therefore it is unregistered on the registering mechanism operated by that rotor. However. the provision of return passage P compensates, at

least in part, for this inaccuracy. That is, a

certain amount of fluid clings to the outer peripheral wall of the rotor as it passes from the measuring chamber, and, rather than being delivered through the outlet, part of this fluid is carried by fluid Wall-friction or cleavage through return passageway P and is thus returned to the inlet side of the flow passage whenceit passes again to the measuring chamber, it being noted that the direction of fluid-travel through passageway P is opposite to that naturally expected by reason of the pressure at the inlet of the flow channel.

. Now the fluid which is thus returned to the measuring chamber has been previously measured and indicated on the meter register in spite of the fact that it was not delivered through the outlet, and thus represents measured but undelivered fluid, hence having the effect of compensating for or balancing slippage uid which has been delivered, but has not been measured. This effect may be expressed as the compensation for slippage past the blades by return of fluid past the barrier block.

The amount of return flow depends upon the clearance between the rotor and lugs |12, |13, which, in effect, cut down, to a predetermined dimension, the thickness of the film of fluid adhering to the rotor, and the parts are proportioned and relatively positioned to give a clearance which will most nearly compensate for the average slippage of the average meter, as determined by test. For instance, where the blades clear the arcuate wall of the measuring chamber by .001", it is found that a clearance of .002" between the rotor and lugs |12, |13 allows such return flow as will approximately compensate for the slippage arising from the specified blade clearance. Of course, these dimensions are given merely by Way of example and are not to be considered as limitative. It has been found by repeated tests that the compensation effected by the return ow acts as described irrespective of the angular velocity of the rotor.

At |85 is indicated a cap bolted at |86 to cover I2, the space between cover and cap representing a gear box indicated at |88. Cap |88 has a depressed central portion |8'| through which extends a shaft |88 carrying gears |89 and |99 at opposite ends thereof. Cap |88 supports the registering mechanism generally indicated at'S and. since this mechanism'may be of any suitable type. it is indicated merely conventionally, but it will be assumed that it is driven from gear |88 through the drive mechanism indicated generally at I9I` Register housing |92 has windows |98 whereby the registering mechanism may be viewed.

Considered broadly, the drive from rotor pinion |99 to gear |89 may be accomplished by any suitable gear train which will properly coordinate the rotor movement (considering its predetermined capacity per revolution) with the registering mechanism, butpreferably, as shown, the drive is accomplished through a train of "changegears generally indicated at |94, whereby the drive to the register mechanism may be varied to compensate for individual characteristics of a given meter. For the purpose of the present application this change-gear" assembly need not be described in detail (as it is in said copending application) but the opposite ends of the train are indicated at |95 and |96, gear |95 being meshed with gear |90, and gear |99 being driven from shaft |91 which extends through stuffing box |99 in cover I2.

Fixed to the lower end of shaft |91 and lying between web l2 and cover I2, is a gear |99 which meshes with rotor gear |39. A thrust bearing 20D is interposed between the hub of gear |99 and the underside of cover I2, while a port 2|II is cut through the gear so, in case the gear-flange 202 should engage the under face of cover I2, uid will be admitted above the gear substantially to equalize the fluid pressure above and beneath the gear and thus prevent it from binding against the cover.

It will be evident that rotation of the rotor will cause register operation through pinion |98, gear |99, shaft |91, change gears I 94 (from gear |99 to gear |95) gear |90, shaft |99, gear |89 and mechanism I9|.

It will be understood various changes in design. structure and arrangement over that herein illustrated and described, may be made without departing from the spirit and scope of the appended claims.

I claim:

1. In a fluid ow mechanism, a casing embodying a barrel with its axis extending vertically and end walls closing the bore of the barrel, said casing having inlet and outlet ports opening to a flow channel defined within the casing, a vertical shaft supported within the casing, a rotor mounted on the shaft for rotation thereabout and movable vertically therealong through a predetermined range, said rotor having blades adapted to extend into said flow channel, a spring tending to urge the rotor vertically upwardly through said range, and acustable means limiting the extent of spring-actuated movement.

2. In a fluid flow mechanism, a casing embodying a barrel with its axis extending vertically and end walls closing the bore of the barrel, said casing having inlet and outlet ports opening to a flow channel defined within the casing, a vertical lshaft stationarily supported within the casing, a

rotor mounted on the shaft for rotation thereabout and having its lower end vertically oppfsed to an interior wall of the casing, and spring suspension means on the shaft resiliently suspending the rotor from the shaft with the lower end of the rotor spaced from said opposing interior wall.

3.V In a fluid flow mechanism, a casing embodying a barrel with its axis Aextending vertically and end walls closing the bore of the barrel, said casing having inlet and outlet ports openingslto a now channel defined within the casing. a vertical shaft supported within the casing, a rotor mounted on the shaft `for rotation thereabout. blades mounted on the rotor and adapted to have substantially radial shuttling movement across the ilow channel, the lower end of the rotor and the lower ends of the blades being vertically opposed to an interior wall of the casing. and spring suspension means on the shaft resiliently suspending the rotor and blades from the shaft with their lower ends vertically spaced from said opposing interior wall of the casing.

4. In a fluid ilow mechanism, a casing embodying a barrel with its axis extending vertically and end walls closing the bore of the barrel, said casing having inlet and outlet ports opening to a flow channel defined within the casing, a vertical shaft supported Within the casing. an upwardly facing shoulder on said shaft, a compression spring about said shaft and seated on said shoulder, a bearing assembly slidable along the shaft and supported by said spring, and a rotor body supported on said bearing assembly.

5. In a fluid flow mechanism, a casing embodying a barrel with its axis extending vertically and end walls closing the bore of the barrel, said casing having inlet and outlet ports opening to a flow channel defined within the casing. a vertical shaft supported within the casing. an upwardly facing shoulder on said shaft, a compression spring about said shaft and seated on said shoulder, a bearing assembly slidable along the shaft and supported by said spring, a rotor body supported on said bearing assembly, and

' means for controlling the effective lifting force of said spring.

6. In a fluid ow mechanism, a casing embodying a barrel with its axis extending vertically and end walls closing the bore of the barrel, said casing having inlet and outlet ports opening to a flow channel defined within the casing, a vertical shaft supported within the casing, an upwardly facing shoulder on said shaft, a compression spring about said shaft and seated on said shoulder. a bearing assembly slidable along the shaft and supported by said spring, a rotor body supported on said bearing assembly, and adjustable means applied to the spring for positively compressing it.

7. In a uid flow mechanism. a casing embodying a barrel with its axis extending vertically and end walls closing the bore of the barrel, said casing having inlet and outlet ports opening to a flow channel dened within the casing, a vertical shaft supported within the casing, an upwardly facing shoulder on said shaft, a compression spring about said shaft and seated on said shoulder, a collar slidable on said shaft and seated on the upper end of said spring, a bearing assembly slidable along said shaft and supported on said collar, a rotor body supported on said bearing assembly, and means for depressing said collar against the action of said spring.

8. In a fluid flow mechanism, a casing embodying a barrel with its axis extending vertically and end walls closing the bore of the barrel, said casing having inlet and outlet ports opening to a flow channel dened within the casing, a vertical shaft supported within the casing, a hollow rotor body rotatably mounted on said shaft, a cam stationarily positioned within the body-hollow, a rotor blade extending radially through a slot in the rotor body and adapted to be projected periodically into the iiow channel, a rock arm pivotally mounted on the body within its hollow, the rock arm being mounted independently of the blade, sad rock arm cooperating with the cam and blade whereby radial thrust is imparted to the blade by the cam by virtue of rotation of the body, and spring suspension me'ans on the shaft resiliently suspending the rotor body and its blade from the shaft and in spaced relation with opposed, underlying portions of the casing.

9. In a iiuid iiow mechanism, a casing embodying a barrel with its axis extending vertically and end walls closing the bore of the barrel, said casing having inlet and outlet ports opening to a fiow channel defined within the casing, a vertical shaft supported within the casing, a hollow rotor body rotatably mounted on said shaft, a cam stationarily positioned within the body-hollow, a rotor blade extending radially through a slot in the rotor body and adapted to be projected periodically into the iiow channel, a rock arm pivotally mounted on the body within its hollow, said rock arm cooperating with the cam and blade whereby radial thrust is imparted to the blade by' the cam by virtue of rotation of the body, spring suspension means on the shaft resiliently suspending the rotor body and its blade from the shaft and in spaced relation with opposed, underlying portions of the casing. and means for shifting said rotor body vertically along the shaft to vary the extent of such spacing and yet maintaining the spring suspension of the rotor and blade.

l0. In a fluid iiow mechanism, a casing embodying a barrel with its axis extending vertically and end walls closing the bore of the barrel, said casing having inlet and outlet ports opening to a iiow channel defined within the casing, a central, stationary shaft extending through the casing bore and through said end walls, means on said shaft and cooperating with said end walls to hold said end walls from centrally spreading apart, a rotor rotatably supported on said shaft and having shuttle blades adapted to be periodically projected into said flow channel, spring suspension means on the shaft resiliently suspending the rotor and its blades with their lower faces in spaced relation with underlying interior walls of the casing, a gear on said rotor, a second gear in mesh with the first mentioned gear and located between the end of the rotor and one of said end walls, and a shaft for said second gear extending through said one end wall.

11. In a fluid ow mechanism, a casing embodying a barrel with its axis extending vertically and end walls closing the bore of the barrel, said casing having inlet and outlet ports opening to a iiow channel defined within the casing, a vertical shaft supported within the casing, a rotor mounted on the shaft for rotation thereabout and movable vertically therealong, a spring tending to urge the rotor vertically upwardly along the shaft. and a stop limiting the extent of springactuated rotor movement.

12. In a uid flow mechanism, a casing embodying a barrel with its axis extending vertically and end walls closing the bore of the barrel, said casing having inlet and outlet ports opening to a flow channel defined within the casing, a central, stationary shaft extending through the casing bore and through said end walls. means on said shaft and cooperating with said end walls to hold said end walls from centrally spreading apart, 'a rotor rotatably supported on said shaft and having shuttle blades adapted to be periodically projected into said flow channel, and spring suspension means on the shaft resiliently suspendlngvthe rotor and its blades with their lower faces in spaced relation with underlying interior walls of the casing.

13. In a fluid iiow mechanism. a casing embodying a barrel with its axis extending vertically and end walls closing the bore of the barrel. said casing having inlet and outlet ports opening to a iiow channel defined within the casing, a vertical shaft stationarily supported within the casing, a rotor mounted on the shaft for rotation thereabout and movable vertically therealong through.

a predetermined range, said rotor having blades adapted to extend into said flow channel, and means controllable from without the casing for moving said rotor within said range to a selected position, said rotor in all its positions of vertical adjustment imposing its down-bearing load on said shaft.

14. In a uid flow mechanism, a casing embodying a barrel with its axis extending vertically and end walls closing the bore of the barrel. said casing having inlet and outlet ports opening to a flow channel defined within the casing. a vertical shaft supported within the casing, a compression spring about said shaft and having its lower end supported thereby, a collar slidable on said shaft and seated on the upper end of said spring, a rotor body supported on said collar and slidable therewith along the shaft, and means for depressing said.' collar against the action of the spring and thereby lowering the rotor along the shaft.

v15. In a fluid flow mechanism, a casing embodying a barrel with its axis extending vertically and end walls closing the bore of the barrel, said casing having inlet and outlet ports opening to a flow channel denedwithin the casing, a vertical shaft supported within the casing, said shaft having an axial bore at one end, one end oi the shaft bore being accessible from the exterior of one end wall and the other end of the shaft bore communicating with the interior of the casing.

a collar slidable verticallyon said shaft, a crosshead connected to the collar and extending through a radial opening in the shaft, which opening communicates with the axial bore, rotor body supported on said collar and slidable therewith along the shaft, and means for controlling the vertical position of the collar with respect to the shaft and including a plunger slidable vertically through the shaft bore and engaged with said cross-head, and adjustable means in the upper end of the shaft bore and actuatable from the exterior of said one end wall for establishing the upper limit of plunger movement.

16. In a fluid ilow mechanism, a casing embodying a barrel with its axis extending vertically and end walls closing the bore of the barrel, said casing having inlet and outlet ports opening to a flow channel defined within the casing, a vertical shaft supported within the casing, said shaft having an axial bore at one end, one end of the shaft bore being accessible from the exterior of one end wall and the other end of the shaft bore communicating with the interior of the casing, a member supported by and slidable vertically with respect to said shaft, a rotor body supported on said member and slidable therewith along the shaft. and means for controlling the vertical position of the member with respect to the shaft and including a plunger slidable vertically through the shaft bore and engaged with said member, adjustable means in the upper end of the shaft bore and actuatable '.from the exterior of said one end wall for establishing the upper limit of plunger movement, and spring means coacting between the shaft and member to urge said member upwardly and thereby resillently hold the plunger at its upper limit. of movement as established by said adjustable means,

17. In a iiuld flow mechanism. a casing embodying a barrel with its axis extending vertically and end walls closing the bore of the barrel, said casing having inlet and outlet ports opening to a flow channel defined withinthe casing, a vertical shaft supported within the casing, arotor mounted on the shaft for rotation thereabout determined range, spring means applied to the rotor in a manner tendingto move the rotor in one direction through-the range, and means controllable from without the casing. for establishing the extent -of such spring-urged movement.

18. In a uid flow mechanism, a casing embodying a barrel and end walls closing the bore of the barrel, said casing having inlet and outlet ports opening to a flow channel dened within the casing, a shaft supported Within the casing, a spring about the shaft and having in eiect, one of its ends engaged therewith, a collar slidable on the shaft and engaged at one end with the other end of said spring. a rotor body slidable along the shaft and hunted in its extent of sliding movement in one direction -by said collar, and means for sliding said collar along the shaft against the action of said spring.

- REUBEN STANLEY SMITH.

CERTIFICATE 0F coRREcTIoN. Patent No. 2,207,2'7LI, July 9, 191m.

` REUBEN 'STANLEY SMITH.

It is hereby certifiedb that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 8, second column, line 7, claim, for the word "openings" read --opening; page 9, first column, line 9, ol-aim 8, for "said" read "said-ug and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

signed and sealed this 10th day of september, A. D. 191m.

Leslie Frazer,

(Seal) Acting Commissioner of Patents. 

